Table 3.
Densities of the most abundant SSR (tri- and tetranucleotide) types in different regions
| Trinucleotide* | Tetranucleotide† | |
| Arabidopsis | ||
| 5'UTR | AAG: 521.9 (74.3%) | AAAG: 41.9 (39.6%) |
| AAC: 48.1 (6.8%) | AAAC: 15.8 (14.9%) | |
| Exons | AAG: 78.2 (35.8%) | AAAG: 1 (28.9%) |
| AGT: 27.7 (12.6%) | AAAC: 0.7 (19.8%) | |
| Introns | AAG: 35.6 (39.1%) | AAAC: 13.4 (22.8%) |
| AAC: 23.1 (25.4%) | AAAG: 12.9 (22%) | |
| 3'UTR | AAG: 60.4 (35.2%) | AAAG: 23.4 (27%) |
| AAC: 33.2 (19.3%) | AAAC: 21 (24.2%) | |
| Genome | AAG: 64.3 (42%) | AAAT: 15.6 (32.5%) |
| AAC: 18.7 (12.2%) | AAAG: 9.3 (19.2%) | |
| Rice | ||
| 5'UTR | CCG: 731.3 (43.8%) | CGAT: 70.6 (20.9%) |
| CCT: 401.3 (24%) | CCCT: 37.4 (11.1%) | |
| Exons | CCG: 218.4 (51.8%) | CCCT: 1.1 (14.3%) |
| CCT: 58.2 (13.8%) | CCCG: 0.8 (10.7%) | |
| Introns | CCG: 74.2 (40.7%) | AAAT: 5.3 (11.4%) |
| CCT: 25.5 (14%) | CGAT: 3.9 (8.5%) | |
| 3'UTR | AAG: 23.5 (15.4%) | CGAT: 18.8 (15.5%) |
| CCG: 22.4 (14.6%) | AATT: 12.5 (10.3%) | |
| Genome | CCG: 86.3 (44.7%) | CGAT: 7.6 (11.9%) |
| AAG: 25.1 (13%) | AAAT: 5.9 (9.2%) |
Each of the repeat types contains all circular permutations of not only the sequence in question, but also of the complement of the sequence. The unit is per mega-base pairs. The percentage indicates how much percent of all repeats of this period are of this type. *Ten possible permutations; †32 possible permuations.